A housewarming party is a party held within approximately 180 days of moving into a new residence. It is an occasion for the hosts to present their new home to their friends, and for friends to give gifts to furnish the new home. Housewarming parties are generally informal; usually there are no planned activities besides a possible tour.
Gifts are customary but not necessary. They usually consist of something for the new house (such as a potted plant, a vase, or a picture frame) or something to be enjoyed during the party (such as a bottle of whiskey, a bouquet of flowers, or a gift basket of foodstuffs). Bluebirds are often given as they are believed to bless the new house with happiness and good luck. In modern day it is also customary to provide bluebird-themed paraphernalia such as china. Pineapples are also common housewarming gifts and the pineapple has served as a symbol of hospitality and warm welcome through the history of the Americas.
In East Lancashire as in parts of Scotland (particularly Ayrshire and Banffshire) a frog is seen as a giver of good luck. A gift of a frog is often made as a wedding or housewarming gift for good luck and fertility.
The term "housewarming" is descended literally from the act of warming a new house, in the days before central heating. Each guest would bring firewood, and build fires in all the available fireplaces, offering firewood as a gift. Aside from warming the house, this was also believed to repel evil spirits by creating a protective atmosphere of warmth. Uninhabited houses were considered targets for vagrant spirits, and therefore required a certain level of cleansing before a house was safe to be occupied by young children.
Origins elsewhere in the world 
In France, housewarming party is called Pendaison de crémaillère, literally "Hanging the chimney hook". Expression comes from medieval times. After the construction was finished, it was a tradition to invite all the participants in the work to eat in order to thank them. The food was prepared in big pot over the fireplace. The heat was controlled by a chimney hook (set the pot higher or lower). This hook was the last thing to be installed while moving in and it marks the beginning of the "thank you meal".
- A housewarming party may be thrown upon completion of renovation or remodel.
- A housewarming party may be presented as an "open house" where people are free to come and go during a fixed window of time on a given day.
- A housewarming may involve a potluck meal.
- Some people invite all of their new neighbors to their housewarming. This allows the hosts to meet their new community.
- In some communities, neighbors may bring the housewarming party to the new residents to welcome them.
- While people try to host a housewarming party within the first 3 months, a lot of people wait until they are completely settled in. The time frame is flexible, and a party can qualify as a housewarming anytime after the move-in date.
- In Thailand the traditional Thai housewarming is a Buddhist ritual where monks, family, friends and food all play an important part. 
- In India, this ceremony is known as "Gruha Pravesh" or "Gruha Pravesham" (Telugu) literally meaning "Entering New House" (for the first time).
- What Would Emily Do (WWED)?, “Best Question” Archive 2005, Emily Post
- "Emily Post Institute—Invitation Etiquette". Emily Post.
- "An A-Z Reference Guide for Solving Your Gift-Giving Dilemmas". Books.google.com. Retrieved 2013-02-18.
- "An Etymological Dictionary of Modern English: In Two Volumes - Ernest Weekley - Google Books". Books.google.co.uk. Retrieved 2013-02-18.
- "Thai Housewarming Ceremony – Monks, Family, Friends & Food » Temple of Thai Food". Templeofthai.com. Retrieved 2013-02-18.